Ethnographic and epidemiologic approaches for the programming of prenatal and birth services in Mesa los Hornos, Mexico

The investigator conducted an action-oriented investigation of pregnancy and birth among the women of Mesa los Hornos, an urban squatter slum in Mexico City. Three aims guided the project: (1) To obtain information for improving prenatal and maternity service utilization; (2) To examine the utility of rapid ethnographic and epidemiologic assessment methodologies; (3) To cultivate community involvement in health development.^ Viewing service utilization as a culturally-bound decision, the study included a qualitative phase to explore women's cognition of pregnancy and birth, their perceived needs during pregnancy, and their criteria of service acceptability. A probability-based community survey delineated parameters of service utilization and pregnancy health events, and probed reasons for decisions to use medical services, lay midwives, or other sources of prenatal and labor and delivery assistance. Qualitative survey of service providers at relevant clinics, hospitals, and practices contributed information on service availability and access, and on coordination among private, social security, and public assistance health service sectors. The ethnographic approach to exploring the rationale for use or non-use of services provided a necessary complement to conventional barrier-based assessment, to inform planning of culturally appropriate interventions.^ Information collection and interpretation was conducted under the aegis of an advisory committee of community residents and service agency representatives; the residents' committee formulated recommendations for action based on findings, and forwarded the mandate to governmental social and urban development offices. Recommendations were designed to inform and develop community participation in health care decision-making.^ Rapid research methods are powerful tools for achieving community-based empowerment toward investigation and resolution of local health problems. But while ethnography works well in synergy with quantitative assessment approaches to strengthen the validity and richness of short-term field work, the author strongly urges caution in application of Rapid Ethnographic Assessments. An ethnographic sensibility is essential to the research enterprise for the development of an active and cooperative community base, the design and use of quantitative instruments, the appropriate use of qualitative techniques, and the interpretation of culturally-oriented information. However, prescribed and standardized Rapid Ethnographic Assessment techniques are counter-productive if used as research short-cuts before locale- and subject-specific cultural understanding is achieved. ^

A case-control study of the risk factors for eclampsia

Objective. To study the risk factors for eclampsia, a rare but significant complication of pregnancy.^ Target population. All deliveries at or after the 20th week of gestation that took place between January 1, 1977 and March 1992, and between January 1990 and April 1992 at two hospitals in Houston, Texas, respectively.^ Study population. Sixty-six confirmed cases of eclampsia, and 2 groups of randomly selected controls: Non-preeclamptic and preeclamptic deliveries matched to cases on hospital and month of delivery on a 1:4 ratio.^ Exclusions. Women with chronic hypertension, gestational epilepsy, a previous history of epilepsy, and convulsions attributed to encephalitis, meningitis, cerebral tumor, and intracerebral bleeding, and women without a definite diagnosis of preeclampsia/eclampsia.^ Results. Eclampsia developed in 0.52-0.93/1000 deliveries. Fifty-six percent of seizures occurred in the antepartum period, 2% as early as 20 weeks of gestation and 39% between 37 and 42 weeks. Twenty-nine percent and 15% occurred in the postpartum and late postpartum periods, respectively, 8% as late as one week postpartum. A different set of risk factors was involved in the development of eclampsia in non-preeclamptic women than in the progression from preeclampsia to eclampsia. Factors involved in the development of eclampsia included, in addition to twin pregnancy and family history of pregnancy-induced hypertension, fewer than 3 prenatal care visits, urinary tract infections, primigravidity, obesity, black ethnicity, diabetes mellitus, and age $\le$20 years. Risk factors involved in the progression from preeclampsia to eclampsia included fewer than 3 of prenatal care visits, and age $\le$20 years. Protective factors were magnesium sulfate administration prior to seizure, history of abortions and longer gestational age. Having less than 3 prenatal care visits and being less than or equal to 20 years of age were predictors of eclampsia, whether of its development or progression from preeclampsia. Once preeclampsia is diagnosed, primigravid, diabetic, black, or obese women and those with urinary tract infections did not appear to exhibit any increased risk for the progression to eclampsia. The administration of magnesium sulfate was especially protective, followed by a positive history of abortions, 3 or more prenatal care visits, and longer gestational age. The protective effect of MgSO$\sb4$ was only slightly diminished when cases were restricted to the 65% who had a diagnosis of preeclampsia. The progression from preeclampsia to eclampsia may be largely preventable through adequate prenatal care and presumably the administration of magnesium sulfate. (Abstract shortened by UMI.) ^

A woman's right to know: A policy review of abortion legislation in Texas

Introduction: Despite its legalization, abortion remains a controversial issue, one that has many divided on either side of the political spectrum. While there have been several changes made to abortion policy over the past few decades, one that continues to have many asking questions is the Woman’s Right to Know Act, a piece of state imposed abortion legislation that has implemented strict restrictions and requirements of women seeking abortion, including pre-abortion mandatory counseling and a 24 hour waiting period. This project analyzed four controversial components of the mandatory counseling materials in Texas in an attempt to examine the scientific validity behind this legislation. Methods: In order to understand the scientific validity behind the content of the preabortion mandatory counseling, I conducted a systematic literature review to analyze: the purported link between abortion and breast cancer, the existence of fetal pain, the risk of abortion to future fertility, and the negative psychological effects of abortion. An electronic search in EBSCO and PubMed of review articles published between 1995 and 2010 resulted in fourteen reviews. Results: Results of the systematic review found (1) inconclusive evidence suggesting a link between abortion and breast cancer, (2) that fetal pain likely does not occur until the third trimester of pregnancy, (3) that associations exist between induced abortion and subsequent preterm birth and placenta previa, and (4) that there is mixed evidence relating to the negative psychological effects that exist among women having had an abortion and those who have not had abortion. Conclusion: Based on these conclusions, a recommendation was made to revise the current state mandated counseling materials to reflect more accurate and scientifically-based information about abortion and its potential risks.^

Associations between ambient levels of combustion pollutants and small for gestational age infants in Texas

There is scant evidence regarding the associations between ambient levels of combustion pollutants and small for gestational age (SGA) infants. No studies of this type have been completed in the Southern United States. The main objective of the project presented was to determine associations between combustion pollutants and SGA infants in Texas using three different exposure assessments. ^ Birth certificate data that contained information on maternal and infant characteristics were obtained from the Texas Department of State Health Services (TX DSHS). Exposure assessment data for the three aims came from: (1) U.S. Environmental Protection Agency (EPA) National Air Toxics Assessment (NATA), (2) U.S. EPA Air Quality System (AQS), and (3) TX Department of Transportation (DOT), respectively. Multiple logistic regression models were used to determine the associations between combustion pollutants and SGA. ^ For the first study looked at annual estimates of four air toxics at the census tract level in the Greater Houston Area. After controlling for maternal race, maternal education, tobacco use, maternal age, number of prenatal visits, marital status, maternal weight gain, and median census tract income level, adjusted ORs and 95% confidence intervals (CI) for exposure to PAHs (per 10 ng/m3), naphthalene (per 10 ng/m3), benzene (per 1 µg/m3), and diesel engine emissions (per 10 µg/m3) were 1.01 (0.97–1.05), 1.00 (0.99–1.01), 1.01 (0.97–1.05), and 1.08 (0.95–1.23) respectively. For the second study looking at Hispanics in El Paso County, AORs and 95% confidence intervals (CI) for increases of 5 ng/m3 for the sum of carcinogenic PAHs (Σ c-PAHs), 1 ng/m3 of benzo[a]pyrene, and 100 ng/m3 in naphthalene during the third trimester of pregnancy were 1.02 (0.97–1.07), 1.03 (0.96–1.11), and 1.01 (0.97–1.06), respectively. For the third study using maternal proximity to major roadways as the exposure metric, there was a negative association with increasing distance from a maternal residence to the nearest major roadway (Odds Ratio (OR) = 0.96; 95% CI = 0.94–0.97) per 1000 m); however, once adjusted for covariates this effect was no longer significant (AOR = 0.98; 95% CI = 0.96–1.00). There was no association with distance weighted traffic density (DWTD). ^ This project is the first to look at SGA and combustion pollutants in the Southern United States with three different exposure metrics. Although there was no evidence of associations found between SGA and the air pollutants mentioned in these studies, the results contribute to the body of literature assessing maternal exposure to ambient air pollution and adverse birth outcomes. ^

Health outcomes, quality improvement and cost-effectiveness of the Community Diabetes Education (CoDE) program: Results of a randomized controlled trial

The objectives of this dissertation were to evaluate health outcomes, quality improvement measures, and the long-term cost-effectiveness and impact on diabetes-related microvascular and macrovascular complications of a community health worker-led culturally tailored diabetes education and management intervention provided to uninsured Mexican Americans in an urban faith-based clinic. A prospective, randomized controlled repeated measures design was employed to compare the intervention effects between: (1) an intervention group (n=90) that participated in the Community Diabetes Education (CoDE) program along with usual medical care; and (2) a wait-listed comparison group (n=90) that received only usual medical care. Changes in hemoglobin A1c (HbA1c) and secondary outcomes (lipid status, blood pressure and body mass index) were assessed using linear mixed-models and an intention-to-treat approach. The CoDE group experienced greater reduction in HbA1c (-1.6%, p<.001) than the control group (-.9%, p<.001) over the 12 month study period. After adjusting for group-by-time interaction, antidiabetic medication use at baseline, changes made to the antidiabetic regime over the study period, duration of diabetes and baseline HbA1c, a statistically significant intervention effect on HbA1c (-.7%, p=.02) was observed for CoDE participants. Process and outcome quality measures were evaluated using multiple mixed-effects logistic regression models. Assessment of quality indicators revealed that the CoDE intervention group was significantly more likely to have received a dilated retinal examination than the control group, and 53% achieved a HbA1c below 7% compared with 38% of control group subjects. Long-term cost-effectiveness and impact on diabetes-related health outcomes were estimated through simulation modeling using the rigorously validated Archimedes Model. Over a 20 year time horizon, CoDE participants were forecasted to have less proliferative diabetic retinopathy, fewer foot ulcers, and reduced numbers of foot amputations than control group subjects who received usual medical care. An incremental cost-effectiveness ratio of $355 per quality-adjusted life-year gained was estimated for CoDE intervention participants over the same time period. The results from the three areas of program evaluation: impact on short-term health outcomes, quantification of improvement in quality of diabetes care, and projection of long-term cost-effectiveness and impact on diabetes-related health outcomes provide evidence that a community health worker can be a valuable resource to reduce diabetes disparities for uninsured Mexican Americans. This evidence supports formal integration of community health workers as members of the diabetes care team.^

Correlates of prenatal care initiation among low -income Hispanic women

Because Hispanic women are even less likely than women of other ethnic groups to receive early prenatal care, the purpose of this study was to identify factors that may influence these women to initiate care. After giving consent, 300 Hispanic women (100 who initiated first trimester care, 100 who initiated second trimester care, and 100 who initiated third trimester care or received no care) were interviewed in the post partum unit of a local public hospital. The interview included recollection of events leading to the first prenatal appointment, including first physical indicators of pregnancy, confirmation of pregnancy, feelings about the pregnancy, appointment making behavior, and system barriers encountered. The Health Belief Model was used as the theoretical framework for determining psychosocial variables. Using this model, perceived susceptibility to problems during pregnancy, perceived seriousness of possible problems, perceived benefits of prenatal care, perceived barriers to care, and cues to action were assessed. Time of entry into prenatal care was assessed by interview.^ In this sample of low-income Hispanic women, a higher perception of barriers to care was associated with later initiation of care and non-use of care, higher perceived benefits of care for the baby were associated with earlier care, especially in women without a card to access hospital district services, and having a card to access hospital district services was associated with earlier care. Several barriers to care were mentioned by women on open-ended questioning including long waiting times, embarrassment, and lack of transportation.^ Recommendations for practice included decreasing the number of visits for low-risk women while increasing the time spent with the provider, decreasing the number of vaginal exams for low-risk women, increasing the use of midwives, training lay workers to do risk assessment, giving specific messages about benefits of care to baby, and increasing general health motivation through community intervention methods. More research on the psychosocial and cultural factors associated with initiation of care is needed. In the meantime, the recommendations for practice can be implemented now to increase the use of prenatal care by low-income Hispanic women. ^

Attitudes of health-care workers toward pregnant, HIV -positive women

The management of HIV infection with antiretroviral drugs has succeeded in increasing survival rates, but the subject of pregnancy in HIV-positive women continues to garner debate. Discrimination and stigma have been identified as barriers to health care, suggesting that women with HIV may be disinclined to seek prenatal care if health-care workers exhibit negative attitudes toward the women's pregnancies. To optimize prenatal and medical care for women with HIV infection, it is important to understand the general social conditions and cultural context in which these women have children. Goffman's treatise on stigma, Foucault's discussion of the knowledge/power matrix, and Bandura's Social Cognitive Theory offer theoretical perspectives by which we can evaluate the gender, race, and class issues that are inherent in pregnancy decision-making for women with HIV infection. It is also necessary to evaluate prevailing attitudes on childbearing toward HIV-positive women and to review the historical background of prejudice in which HIV-positive women make decisions regarding childbearing. ^ This qualitative study used a survey instrument and one-on-one interviews with HIV-infected women to elicit their perceptions of how they were treated by care providers when they became pregnant. It also included interviews with health-care workers to determine what their feelings are about pregnancy within the context of HIV infection. Results of the ethnographic inquiry reveal that most of the women had negative experiences at some point during a pregnancy, but that the situation improved when they sought care from a provider who was familiar with HIV infection. The health-care providers interviewed were firm in their belief that HIV-positive women deserved optimal care and treated the women with respect, but these are individuals who are also experts in providing care to HIV-positive patients. The question remains as to what kind of care HIV-positive women are receiving generally and what types of attitudes they are being subjected to if they see less experienced providers. Further research is also needed to determine whether HIV-positive women from a broader ethnic representation and higher socioeconomic status experience similar negative attitudes. ^

Knowledge of medical abortion among Brazilian medical students

OBJECTIVE: To assess the knowledge of Brazilian medical students regarding medical abortion (MA) and the use of misoprostol for MA, and to investigate factors influencing their knowledge. METHODS: All students from 3 medical schools in São Paulo State were invited to complete a pretested structured questionnaire with precoded response categories. A set of 12 statements on the use and effects of misoprostol for MA assessed their level of knowledge. Of about 1260 students invited to participate in the study, 874 completed the questionnaire, yielding a response rate of 69%. The Ï (2) test was used for the bivariate analysis, which was followed by multiple regression analysis. RESULTS: Although all students in their final year of medical school had heard of misoprostol for termination of pregnancy, and 88% reported having heard how to use it, only 8% showed satisfactory knowledge of its use and effects. Academic level was the only factor associated with the indicators of knowledge investigated. CONCLUSION: The very poor knowledge of misoprostol use for MA demonstrated by the medical students surveyed at 3 medical schools makes the review and updating of the curriculum urgently necessary.

Adaptaciones cardiacas hemodinámicas, estructurales y funcionales a un programa de ejercicio físico supervisado durante el embarazo: ensayo clínico aleatorizado = Hemodynamic, structural and functional cardiac adaptations in a supervised physical exercise program during pregnancy: a randomized controlled trial

Introducción: Diversos cambios ocurren en el sistema cardiovascular materno durante el embarazo, lo que genera un gran estrés sobre este sistema especialmente durante el tercer trimestre, pudiendo acentuarse en presencia de determinados factores de riesgo. Los objetivos de este estudio fueron, valorar las adaptaciones cardiovasculares producidas por un programa específico de ejercicio físico; su seguridad sobre el sistema cardiovascular materno y los resultados del embarazo; y su eficacia en el control de los factores de riesgo cardiovascular. Material y métodos: El diseño del estudio fue un ensayo clínico aleatorizado. 151 gestantes sanas fueron evaluadas mediante un ecocardiograma y un electrocardiograma en la semana 20 y 34 de gestación. Un total de 89 gestantes participaron en un programa de ejercicio físico (GE) desde el primer hasta el tercer trimestre de embarazo, constituido principalmente por 25-30 minutos de trabajo aeróbico (55-60% de la frecuencia cardiaca de reserva), trabajo de fortalecimiento general y específico, y un trabajo de tonificación del suelo pélvico; desarrollado 3 días a la semana con una duración de 55-60 minutos cada sesión. Las gestantes aleatoriamente asignadas al grupo de control (GC; n=62) permanecieron sedentarias durante el embarazo. El estudio fue aprobado por el Comité Ético de investigación clínica del Hospital Universitario de Fuenlabrada. Resultados: Las características basales fueron similares entre ambos grupos. A diferencia del GC, las gestantes del GE evitaron el descenso significativo del gasto cardiaco indexado, entre el 2º y 3ºT de embarazo, y conservaron el patrón geométrico normal del ventrículo izquierdo; mientras que en el GC cambió hacia un patrón de remodelado concéntrico. En la semana 20, las gestantes del GE presentaron valores significativamente menores de frecuencia cardiaca (GC: 79,56±10,76 vs. GE: 76,05±9,34; p=0,04), tensión arterial sistólica (GC: 110,19±10,23 vs. GE: 106,04±12,06; p=0,03); tensión arterial diastólica (GC: 64,56±7,88 vs. GE: 61,81±7,15; p=0,03); tiempo de relajación isovolumétrica (GC: 72,94±14,71 vs. GE: 67,05±16,48; p=0,04); y un mayor tiempo de deceleración de la onda E (GC: 142,09±39,11 vs. GE: 162,10±48,59; p=0,01). En la semana 34, el GE presentó valores significativamente superiores de volumen sistólico (GC: 51,13±11,85 vs. GE: 56,21±12,79 p=0,04), de llenado temprano del ventrículo izquierdo (E) (GC: 78,38±14,07 vs. GE: 85,30±16,62; p=0,02) y de tiempo de deceleración de la onda E (GC: 130,35±37,11 vs. GE: 146,61±43,40; p=0,04). Conclusión: La práctica regular de ejercicio físico durante el embarazo puede producir adaptaciones positivas sobre el sistema cardiovascular materno durante el tercer trimestre de embarazo, además de ayudar en el control de sus factores de riesgo, sin alterar la salud materno-fetal. ABSTRACT Background: Several changes occur in the maternal cardiovascular system during pregnancy. These changes produce a considerable stress in this system, especially during the third trimester, which can be increased in presence of some risk factors. The aims of this study were, to assess the maternal cardiac adaptations in a specific exercise program; its safety on the maternal cardiovascular system and pregnancy outcomes; and its effectiveness in the control of cardiovascular risk factors. Material and methods: A randomized controlled trial was designed. 151 healthy pregnant women were assessed by an echocardiography and electrocardiography at 20 and 34 weeks of gestation. A total of 89 pregnant women participated in a physical exercise program (EG) from the first to the third trimester of pregnancy. It consisted of 25-30 minutes of aerobic conditioning (55-60% of their heart rate reserve), general and specific strength exercises, and a pelvic floor muscles training; 3 times per weeks during 55-60 minutes per session. Pregnant women randomized allocated to the control group (CG) remained sedentary during pregnancy. The study was approved by the Research Ethics Committee of Hospital Universitario de Fuenlabrada. Results: Baseline characteristics were similar between groups. Difference from the CG, pregnant women from the EG prevented the significant decrease of the cardiac output index, between the 2nd and 3rd trimester of pregnancy, and preserved the normal left ventricular pattern; whereas in the CG shifted to concentric remodeling pattern. At 20 weeks, women in the EG had significant lower heart rate (CG: 79,56±10,76 vs. EG: 76,05±9,34; p=0,04), systolic blood pressure (CG: 110,19±10,23 vs. EG: 106,04±12,06; p=0,03); diastolic blood pressure (CG: 64,56±7,88 vs. EG: 61,81±7,15; p=0,03); isovolumetric relaxation time (GC: 72,94±14,71 vs. GE: 67,05±16,48; p=0,04); and a higher deceleration time of E Wave (GC: 142,09±39,11 vs. GE: 162,10±48,59; p=0,01). At 34 weeks, the EG had a significant higher stroke volume (CG: 51,13±11,85 vs. EG: 56,21±12,79 p=0,04), early filling of left ventricular (E) (CG: 78,38±14,07 vs. EG: 85,30±16,62; p=0,02) and deceleration time of E wave (CG: 130,35±37,11 vs. EG:146,61±43,40; p=0,04). Conclusion: Physical regular exercise program during pregnancy may produce positive maternal cardiovascular adaptations during the third trimester of pregnancy. In addition, it helps to control the cardiovascular risk factors without altering maternal and fetus health.

Luteinizing hormone induction of ovarian tumors: Oligogenic differences between mouse strains dictates tumor disposition

The use of fertility drugs has continued to grow since their introduction in the 1960s. Accompanying this increase has been the speculation that repetitive use of these drugs can cause ovarian tumors or cancer. We recently reported that transgenic mice with chronically elevated luteinizing hormone (LH), an analog of which is commonly used in fertility regimens, develop granulosa cell (GC) tumors. In this report we show that LH induction of these tumors is highly dependent on genetic background. In CF-1 mice, chronically elevated LH invariably causes GC tumors by 5 months of age. However, in hybrid mice generated by crossing CF-1 males with C57BL/6, SJL, or CD-1 females, elevated levels of this same hormone cause a completely different phenotype resembling a luteoma of pregnancy. We also show that three genes likely control these alternative hormonal responses. This clinical correlate of elevated LH reveals remarkably distinct, strain-dependent, ovarian phenotypes. In addition, these results support the rare incidence of GC tumors in the human population, and suggest that the ability of certain fertility drugs to cause ovarian tumors may depend on an individual's genetic predisposition.

Parent–progeny recognition as a function of MHC odortype identity

The several linked polymorphic genes of the MHC, which has been proposed as a prime determinant of sensed genetic individuality within species, is known to operate in mice by olfactory recognition in aspects of reproductive behavior that concern mate selection, thereby favoring outbreeding and heterozygosity, and also concern the maintenance of pregnancy. A single base-change can alter an individual MHC odortype, and the potential range of combinatorial MHC-determined odortypes is clearly vast. Following our findings that newborn mice already express their MHC odortype (which is detectable at 9 days of gestational age), we sought to determine whether MHC is involved in behavioral aspects of early development, such as rearing. In the studies presented herein, we report the ability and proclivity of mothers to recognize and preferentially retrieve syngeneic (genetically identical) pups from other pups differing only for MHC. Reciprocally, we report the ability of pups to recognize their familial environment, regardless of whether they had been nursed by their biological mothers or by foster mothers. Early learning experiences of the MHC environment are apparently a key element in survival, assuring maternal protection and promoting outbreeding.

Identification of a renal-specific oxido-reductase in newborn diabetic mice

Aldose reductase (ALR2), a NADPH-dependent aldo-keto reductase (AKR), is widely distributed in mammalian tissues and has been implicated in complications of diabetes, including diabetic nephropathy. To identify a renal-specific reductase belonging to the AKR family, representational difference analyses of cDNA from diabetic mouse kidney were performed. A full-length cDNA with an ORF of 855 nt and yielding a ≈1.5-kb mRNA transcript was isolated from a mouse kidney library. Human and rat homologues also were isolated, and they had ≈91% and ≈97% amino acid identity with mouse protein. In vitro translation of the cDNA yielded a protein product of ≈33 kDa. Northern and Western blot analyses, using the cDNA and antirecombinant protein antibody, revealed its expression exclusively confined to the kidney. Like ALR2, the expression was up-regulated in diabetic kidneys. Its mRNA and protein expression was restricted to renal proximal tubules. The gene neither codistributed with Tamm–Horsfall protein nor aquaporin-2. The deduced protein sequence revealed an AKR-3 motif located near the N terminus, unlike the other AKR family members where it is confined to the C terminus. Fluorescence quenching and reactive blue agarose chromatography studies revealed that it binds to NADPH with high affinity (KdNADPH = 66.9 ± 2.3 nM). This binding domain is a tetrapeptide (Met-Ala-Lys-Ser) located within the AKR-3 motif that is similar to the other AKR members. The identified protein is designated as RSOR because it is renal-specific with properties of an oxido-reductase, and like ALR2 it may be relevant in the renal complications of diabetes mellitus.

Dual control of LIF expression and LIF receptor function regulate Stat3 activation at the onset of uterine receptivity and embryo implantation

Leukemia inhibitory factor (LIF) expression in the uterus is essential for embryo implantation in mice. Here we describe the spatial and temporal regulation of LIF signaling in vivo by using tissues isolated from uteri on different days over the implantation period. During this time, LIF receptors are expressed predominantly in the luminal epithelium (LE) of the uterus. Isolated epithelium responds to LIF by phosphorylation and nuclear translocation of signal transducer and activator of transcription (Stat) 3, but not by an increase in mitogen-activated protein kinase levels. The related cytokines Il-6, ciliary neurotrophic factor, as well as epidermal growth factor, do not activate Stat3, although epidermal growth factor stimulates mitogen-activated protein kinase. In vivo Stat3 activation is induced by LIF alone, resulting in the localization of Stat3 specifically to the nuclei of the LE coinciding with the onset of uterine receptivity. The responsiveness of the LE to LIF is regulated temporally, with Stat activation being restricted to day 4 of pregnancy despite the presence of constant levels of LIF receptor throughout the preimplantation period. Uterine receptivity is therefore under dual control and is regulated by both the onset of LIF expression in the endometrial glands and the release from inhibition of receptor function in the LE.

Cloning and expression of Stat5 and an additional homologue (Stat5b) involved in prolactin signal transduction in mouse mammary tissue.

Prolactin (PRL) induces transcriptional activation of milk protein genes, such as the whey acidic protein (WAP), beta-casein, and beta-lactoglobulin genes, through a signaling cascade encompassing the Janus kinase Jak2 and the mammary gland factor (MGF; also called Stat5), which belongs to the family of proteins of signal transducers and activators of transcription (STAT). We isolated and sequenced from mouse mammary tissue Stat5 mRNA and a previously unreported member, which we named Stat5b (Stat5 is renamed to Stat5a). On the protein level Stat5a and Stat5b show a 96% sequence similarity. The 5' and 3' untranslated regions of the two mRNAs are not conserved. Stat5a comprises 793 amino acids and is encoded by a mRNA of 4.2 kb. The Stat5b mRNA has a size of 5.6 kb and encodes a protein of 786 amino acids. Both Stat5a and Stat5b recognized the GAS site (gamma-interferon-activating sequence; TTCNNNGAA) in vitro and mediated PRL-induced transcription in COS cells transfected with a PRL receptor. Stat5b also induced basal transcription in the absence of PRL. Similar levels of Stat5a and Stat5b mRNAs were found in most tissues of virgin and lactating mice, but a differential accumulation of the Stat5 mRNAs was found in muscle and mammary tissue. The two RNAs are present in mammary tissue of immature virgin mice, and their levels increase up to day 16 of pregnancy, followed by a decline during lactation. The increase of Stat5 expression during pregnancy coincides with the activation of the WAP gene.

Evidence suggesting that the odortypes of pregnant women are a compound of maternal and fetal odortypes.

Odortypes--namely, body odors that distinguish one individual from another on the basis of genetic polymorphism at the major histocompatibility complex and other loci--are a fundamental element in the social life and reproductive behavior of the mouse, including familial imprinting, mate choice, and control of early pregnancy. Odortypes are strongly represented in urine. During mouse pregnancy, an outcrossed mother's urine acquires fetal major histocompatibility complex odortypes of paternal origin, an observation that we took as the focus of a search for odortypes in humans, using a fully automated computer-programmed olfactometer in which trained rats are known to distinguish precisely the odortypes of another species. Five women provided urine samples before and after birth, which in each case appropriately trained rats were found to distinguish in the olfactometer. Whether this olfactory distinction of mothers' urine before and after birth reflects in part the odortype and hence genotype of the fetus, and not just the state of pregnancy per se, was tested in a second study in which each mother's postpartum urine was mixed either with urine from her own infant or with urine of a different, same-aged infant. Responses of trained rats were more positive with respect to the former (congruous) mixtures than to the latter (incongruous) mixtures, implying that, as in the mouse, human fetal odortypes of paternal genomic origin are represented in the odortype of the mother, doubtless by circulatory transfer of the pertinent odorants.